Hull Vane

"The Hull Vane® only reduces the pressure resistance (not the resistance associated with friction).

That sentence above makes it sound like Mr. Bernoulli's principle is at work in some way.

Not Bernoulli. Think Coanda.

Didn't Oceanfast/Phil Curran try something similar with 'Ocean Seven'?

Somewhere in the back of what's left of my mind, I remember talk of a foils being fitted at the stern sections. That was 20 odd years ago, so may be mistaken.

I know what you mean


Wasn't there a sailboat that a feature was written about here at YF that instead of traditional sails the boat had vertical vanes shaped like a airfoil? I seem to remember 2 or 4 of them at least. Is this the same principle except the working fluid is water instead of air?

In aero... hydro and fluid dynamics... the important part really is where it comes all back together...

The leading edge or bow is important and lots has been done to diminish bow wave and change their form... but much of the drag is created at the stern which is where these boys are trying to improve things.

You know that rough turbulent "wake" that usually tails 'power' boats... ain't all prop wash!

Is this of similar concept?

Navatek Ltd.

Is this the link pertaining to air bubbles?

Mitsubishi reduces friction on ship hulls by blowing bubbles

While we are digressing, wonder if Mitsubishi will use a pair of these in their PanaMax version?

Most powerful diesel engine in the world

How this "hull vane" works is by modifying the flow and induced drag conditions at the stern of the boat. If you think of the bow bulb concept it is similar but effecting the situation on the more important trailing edge of the hydrodynamic body/hull.

In both the movement of the hull through the water induces kinematic energy effects in the water as the hull moves. Theoretically without considering wave or current action an ideally shaped hull would simply separate the still water and move it out of the way with a while imparting a minimum of disruption or "movement of the water"... only enough to allow the passage of the hull. The stationary water would be separated by the leading edge or bow and smoothly accelerated to just enough velocity to move out of the way to allow the shape of the hull to pass and then be equally and smoothly decelerated back to the still state at the trailing edge or stern. Only enough energy of movement "kinematic effects" and velocity would be imparted to to water to move it out of the way and then put it back together again with no net gain in movement or velocity in the water. The quantity of water moved; the distance it has to be moved; how fast it has to be moved, and how smoothly it is moved out of the way all add up to take energy. Reduce any or all of those and you reduce the energy required in doing so, except understandly smooth really means the less abruptly. Logically each of these translate into displacement mass of the hull, volume (which is directly related to mass), speed of hull and streamlining.

This is the fundamental of all hydro and aero dynamics. The loss of energy in doing this is called drag or more properly induced drag of form... wherein the form refers to the shape of the hull or object moving through the water.

However, water is viscus and this spreads the energy effects out to effect water not directly involved in the getting out of the way... so more water is effected by the viscus effects.

Also, the velocity and energy imparted to the water take time to dissipate spreading the effects of the water moving out of the way.

The hull vane is an attempt to use the velocity/kinematic energy of the action of the movement of the hull to direct that in a manner to effect and improve the effective streamline of the hull at the point of the trailing edge or stern wherein the water is put back as best as possible its original state prior to the passage of the hull.

I have not gone into skin drag or turbulence to explain the real reason for this design... nor of the effect of propulsion.

Hull Vane explained

Hi, sorry to revive an old thread, but there are some new developments on this front.

Disclaimer: I work for Hull Vane - my apologies if this is considered as a commercial post, but I think the Hull Vane is such an innovative fuel saving device that it also has "news value". Along with ferries and naval vessels, yachts (of semi-displacement and displacement type) are in the category of ships which sail at a relatively high speed, where the Hull Vane can provide significant savings (>10%).

To understand the working principles of the Hull Vane, the easiest is to watch this short video: Hull Vane - Fuel Saving Foils - YouTube

Because clients for the Hull Vane are often ship or yacht owners and not shipyards, a separate company was established to market, design and produce the Hull Vane. It can easily be retrofitted to an existing yacht or incorporated into the design from the beginning.

For more information, have a look on www.hullvane.com or catch up with me at the Monaco Yacht Show next week.

No, we'll be walking around.

Wonder if JWY encountered the Hull Vane?

http://www.yachtforums.com/forums/general-yachting-discussion/23516-ibex-new-innovations.html

Would seem the Hull Vane is not new news, more like yesterday's news.

Van Oossanen Naval Architects – Van Oossanen?s Hull Vane: Nose jobs are out, butt lifts are the latest fashion

I think it is a good idea. And, it should increase performance / economy as claimed. I should be an easy install too or retrofit too. So it should be a winner.

Most innovations are new applications of old ideas. Hydrofoils and the concepts have been around for decades, actually centuries as they were first worked on around 1898-1900.

If the Heesen application is successful and marketable, meaning yacht buyers will pay extra for it or will purchase Heesen because they have it, then I would expect to see an expansion. But we're in an industry of followers.

I also don't know the cost of it, but if the application works well and the demand is there, then I'm sure others will come out with slightly different foil systems. Probably patent fights ensue.

I think the concept of Hull Vane though is a very interesting approach as it's not meant to lift an entire boat off the water, it's just meant to provide lift enough to improve performance moderately. I think by being less extreme it could be far more practical and successful long term. I look at it potentially as another device that could be standard on large boats and thought of in the same way we currently think of stabilizers, as the norm.

Harry Larsen once fitted hydrofoils on a 24' Bayliner.

https://www.youtube.com/watch?v=w54-OEWulDE

ECO had a foil as well Francis Design

But I am not sure it is only good to have something attached there? I think on new yachts, it is better to design a hull that is good enough without it...